The St. Thomas police officer who pleaded guilty Tuesday to sexual interference involving a teenage girl he met when she requested a background check also created a fake persona as a London firefighter to simultaneously dupe the girl online, court heard.

St. Thomas police Const. Garry Christiansen, 57, pleaded guilty to incidents that involved a girl younger than 16 between January 2016 and May 2017. The agreed statement of facts read into court Tuesday veered from disturbing to downright bizarre.

Court heard that the victim met Christiansen when she went to get a police record check at the St. Thomas police station, where Christiansen was working the front desk. Christiansen and the victim began a months-long sexual relationship, but didn’t engage in sexual intercourse until the victim turned 16, according to the agreed statement of facts.

At one point, court heard, Christiansen led the girl to believe he had a friend in London who was a firefighter who wanted to have sex with her. Christiansen used a secret cellphone to exchange text messages with the girl while impersonating the fictitious firefighter, court heard.

Christiansen was arrested in October 2017 and suspended by the St. Thomas police department at that time. Christiansen made $107,000 in 2018 while suspended. Ontario is the only Canadian province that won’t allow police chiefs to suspend without pay officers facing internal discipline or criminal charges.

He pleaded guilty Tuesday to just one charge, sexual interference. Christiansen will be back in court Sept. 18 to be sentenced.

Former St. Thomas police Const. Garry Christiansen, left, and lawyer Lucas O’Hara leave the Elgin County Courthouse Tuesday after Christiansen pleaded guilty to sexual interference with a girl under the age of 16. (LAURA BROADLEY, Times-Journal)

In a Tuesday statement, St. Thomas police Chief Chris Herridge called the entire situation “a difficult time for the victim, the community and our police service.”

Herridge said Christiansen has resigned from the police department.

“It is always very disappointing when an officer is charged with a criminal offence,” Herridge wrote. “It is disheartening for our members and we understand it is for the community as well.”

He added: “I want to assure the community, especially the victim in this matter, that this is not a reflection of our women and men who work so hard every day to uphold the law and keep our communities safe.”